Badar N'D'D was a member of the Antican species, who were enemies of the Selay. In 2364, he served as the chief delegate to the Parliament conference, where his people attempted to resolve their differences with their enemies, the Selay.
Both the Anticans and the Selay wished to join the United Federation of Planets, but the Federation insisted that the differences between the two races be resolved first. The conference, which was held at the neutral planet of Parliament, was set up for this purpose.
Badar and his delegation, as well as the Selay delegation, were transported to Parliament aboard the USS Enterprise-D. Upon arriving on the Enterprise-D, Badar N'D'D and his delegation were kept as far from the Selay as possible. (TNG: "Lonely Among Us")
Badar N'D'D was played by Star Trek recurring guest actor Marc Alaimo who received no credit for his appearance. This was one of first of several roles played by Alaimo. Due to Alaimo's appearance as an Antican, Michael Westmore had a cast of the actor's head. It inspired Westmore when he came to design the look of the Cardassians, as Alaimo later played the first Cardassian who appeared in Star Trek. (Star Trek: Aliens & Artifacts, p. 80)
The name Badar N'D'D is taken from the script and was not spoken on-screen. As such, the exact pronunciation is unknown.